Few species found in the Erdre river – Nantes (France)

On this video, two things looks to me very interesting. First the fact that this Rotifer (?) is attached to a Daphnia (cf. post : Inside the eye of a Daphnia). The second one is the sort of ball attached to this Rotifer, any idea ?

This Copepode is interestingly covered by what looks to be algae since they are green. I never saw something like this.